Process of hardening and tempering copper.



UNrrn Sra'rns CARRIE RENSTBOM PLUMER,

Patented June 13, 1905.

ATENT @rricn.

OF SEATTLE, \VASHINGTON.

SPECIFICATION forming part of Letters Patent No. 792,070, dated June 13, 1905. Application filed June 18, 1904. Serial No. 213,172.

To all whom it may concern:

Be it known that I, CARRIE RENsTROM PLUMER, a citizen of the United States, residing at Seattle, in the county of King and State of Washington, have invented certain new and useful Improvements in Processes of Hardening and Tempering Copper; and I do hereby declare thefollowing tobe a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a process for hardening copper and the alloys of copper; and the same comprises subjecting copper or alloys of copper to heat of a high temperature and while in a heated condition subjecting the same to the action of sulfate of copper, (blue vitriol,) then partially cooling, and then subjecting it to the action of sulfur.

The process also comprises subjecting cop per or alloys of copper to heat of a high temperature and while in a heated condition subjecting the same to the action of sulfate of copper (blue vitriol) and then pouring the metal into molds and forming the same into desired shapes and allowing the metal to partially cool, and finally subjecting it to the action of sulfur until it is coated with sulfuroil and then allowing the metal to harden.

In carrying out' my process copper or an alloy of copper is heated to a molten condi tion in a crucible, and while in this condition the same is treated to the action of sulfate of copper (blue vitriol) in from one to twenty ounces of sulfate of copper to each one hundred pounds of copper or alloy of copper, the sulfate of copper being preferably in a pulverized condition. The metal may then be poured off into molds and formed into the desired shapes or articles and is then taken from the molds before it has completely cooled and treated with sulfur, the latter preferably in a pulverized condition. The sulfur is applied when the metal is of such a temperature that it will not burn up the sulfur, but merely form an oil upon the surface of the metal, sufficient sulfur being applied to form a complete covering of the oil over the surface of the metal. The metal is then preferablylaid aside with this coating of sulfur upon it to cool and to stand from ten to forty-eight hours, the period of so standing to be increased or decreased within this limit, ac cording to the toughness and hardness of the metal product desired. The sulfate of copper when applied to the molten copper or alloy of copper will in part evaporate and in part be taken up by the copper or alloy, its effect being to harden the mass. The effect of the sulfur applied to the copper or alloy is to further harden the same. Different alloys may be made and successfully treated with my process. For instance, where a product is desired suitable for bearing metals, for steam packing-rings, journals, pumps, &c., I have found an alloy of tin and copper in the pro portion of from one to twenty per cent. of tin and the balance copper very suitable. To this alloy when in a molten condition is added sulfate of copper and black antimony in the proportion of one to ten ounces of antimony to one hundred pounds of metal. The effect of the antimony is to harden the tin.

In the hardening of copper or its alloy I find that when the metal has cooled to a certain degree, which must be determined by experiments, the application of sulfur will produce upon the surface of the metal a substantially black oil which spreads over the entire surface. This oil I have termed throughout the specification and claims sulfur-oil. If the sulfur-oil is applied to metal when at too high a degree of temperature, the sulfur will simply burn off, or if the metal is permitted to cool until its degree of temperature is toolow a yellow liquid will form where the sulfur is deposited, which liquid produces little, if any, beneficial results. Therefore I am careful to apply the sulfur upon the metal when at just the right heat for producing a black or blue-black oil or liquid which when allowed to remain on the metal produces a hardening and toughening effect upon the metal.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The herein-described process of hardening copper or the alloys of copper comprising subjecting copper or alloys of copper to heat ing the same into desired shapes and allowing the metal to partially cool, and'finally subjecting it to the action of sulfur until it is coated with sulfur-oil, and then allowing the metal to harden.

In testimony whereof I hereunto a'ffix my signature in presence of two Witnesses.

CARRIE ll-ENSTROM PLUMER.

W' itnesses G. ARD KEMP, E. N. MARTIN. 

